使用泛型类，通常是需要对类中的某些成员，比如某些field和method中的参数或变量，进行统一的类型限制，这样可以保证程序更好的健壮性和稳定性。
泛型类
class Student[T] (var Id:T)
{
def getId(stuid :T) ="学生的ID"+id+stuid
}
var s=new Student[Int](23)
泛型函数
def getCard[T] (context:T){
if(context.isInstanceOf[Int])
"本ID是001"+context
else if(context.isInstanceOf[String])
"this card"+context
else "card"+context
}
getCard[Int](233)
泛型类边界类
class Person(var name:String){
def sayHello=println("hello,i'm"+name)
def makeFriends(Person p){
sayHello
p.sayHello
}
class Party[ T<: Person]（p1 T,p2 T）{//下边界
p1.makeFriends(p2)
}
}
##--------------------------------------------------------------------------------------------------
class Person(val name:String)
class Student(val name:String) extends Father(name:String)
def getDcard[R>:Student]( Person p){
if(person.getClass==class(P) )println("1234567890")
else if(person.getClass==class(Student) println(" good student")
}
View Bounds 除了上下边界以外，支持出父子关系以外的多种类型相互转换
class Person(name:String){
def sayHello=println("good meeting everyone")
def mkfriends(p:Person{
sayHello
p.sayHello
}
}
class Student(name:String) extends Person(name)
class Dog(name:String){
def sayHello=println("we are family")
}
implicit def dogtoPerson(dog:Object):Person=if(dog.isInstanceOf[Dog]){
var _dog=dog.asInstanceOf(Dog)
new Person(_dog.name)
} else Nil
class Party[T<%Person](t1 T,t2 T)
泛型数组 实例化一个泛型数组
class Meat (val name:String)
class Vegatable(name:String)
def packageFood[T :Manifest](food:T*) {
var foodpakage=new Array[T](food.length)
for(i<-0 until food.length) foodPackage(i)=food(i)
foodpakage
}
泛型数组Array[_]
